Thermokarst lakes form as ice thaws in permafrost-affected ground, creating landscapes dotted with lakes. These form a valuable component of socioecological systems in central Yakutia. Lake formation also influences the carbon balance. We are investigating novel ways to characterise volumes of carbon and ice lost via thermokarst using remote-sensing approaches.
Start date: 1/8/2015
End date: 31/07/2017
A major concern related to climate warming in high latitudes is that of permafrost thaw, which disrupts the land surface and leads to greenhouse gas emissions as once frozen soil and sediment become mobile and subject to decay. Thaw on level surfaces can lead to downward ground collapse and the formation of lakes (thermokarst lakes), which dominate many northern regions. In Yakutia, near the Siberian “cold pole”, extremely cold winters have preserved permafrost since the last ice age, but this is now changing with global warming, which is particularly strong in this region. Established lakes near Yakutsk that are important for local livelihoods are showing water-level fluctuations as underlying permafrost degrades, and in other locations new lakes are forming due to disturbance of the land surface by humans or by fire. We are exploring the use of remote sensing techniques to classify lakes and estimate their volumes. This should allow us to characterize past rates of ground collapse, ice loss and potential carbon loss to the atmosphere as a background, or benchmark, against which to assess current and future change.